Îõ³h* } È$      !"#0.4.1(c) 2011 Brent YorgeyBSD-style (see LICENSE)byorgey@cis.upenn.edu Safe-InferredÍÛÝ € force-layout×A particle has a current position, current velocity, and current force acting on it. force-layoutAn Ensembleª is a physical configuration of particles. It consists of a mapping from particle IDs (unique integers) to particles, and a list of forces that are operative. Each force has a list of edges to which it applies, and is represented by a function giving the force between any two points.  force-layout*An edge is a pair of particle identifiers.  force-layout$Used to uniquely identify particles. force-layout